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Why Did the NBA Miss On Jeremy Lin?

In my last post, I reviewed how difficult it was to evaluate quarterbacks in the NFL draft. Essentially, I noted that there were several factors connected to where a quarterback was selected in the draft. But those factors failed to predict future performance. Given how difficult it was to just predict the future performance of veterans in the NFL, the difficulty people have forecasting the NFL performance of college quarterbacks is not surprising. In sum, “mistakes” on draft day in the NFL simply reflect the immense complexity of the problem.

In the NBA, though, it is a very different story. Veteran NBA players – relative to what we see in the NFL – are far more consistent over time. And although we cannot predict future NBA performance on draft day perfectly, we certainly know something. Part of that “something” that we know is that NBA teams make mistakes by focusing on the “wrong” factors. To illustrate, let’s talk about Jeremy Lin.

Right now, people are wondering how a player like Lin could have been missed by NBA decision-makers. The research I published with Aju Fenn and Stacey Brook in the Journal of Productivity Analysis last year (research discussed inStumbling On Wins) might help some shed some light on this issue.

Our paper looked at the NBA draft from 1995 to 2009. The first issue we considered was which factors impacted where a player was drafted. The following table (fromStumbling On Wins) lists the factors that we considered. On the left are the factors that we found statistically impacted draft position, and on the right are the factors that we found didn’t matter.

What Explains Draft Position in the NBA?

Improve Draft Position

Don’t Help Draft Position

Points Scored*

Rebounds*

Shooting Efficiency from Two-Point Range

Turnovers*

Shooting Efficiency from Three-Point Range

Free Throw Percentage

Assists*

Player’s Race

Steals *

Playing Center

Blocked Shots*

Playing Power Forward

Height, relative to position played

Playing Point Guard

Playing in the Final Four the year drafted

Playing for an NCAA Champion the year drafted

Playing in a Major Conference

Lower Draft Position

Players age when drafted

Personal Fouls*

Playing Shooting Guard

* – per 40 minutes played, adjusted for position played

In the above table we see that being able to rebound, avoid turnovers, and hit free throws doesn’t impact a player’s draft position. However, there were seven box score statistics that did matter. Of these – as the following table (again, taken from Stumbling on Wins) notes – points scored had by far the largest impact on draft position. Such a result is consistent with past studies of free agent salaries, research on who gets cut from NBA teams, the voting for the All-Rookie team (by the NBA coaches), and the coaches’ allocation of minutes. Yes, scoring dominates player evaluation in the NBA and the domination begins on draft night.

The Impact of a One Standard Deviation Increase in Statistically Significant Performance Variables

Variable

Draft Slots Gained from a One Standard Deviation Increase

Points

6.3

Blocked Shots

3.9

Personal Fouls

2.5

Assists

2.2

Two point field goal percentage

1.9

Steals

1.4

Three point field goal percentage

1.3

Given these results, let’s look at Jeremy Lin’s stats when his college career ended in 2010. Here is what we knew about Lin at that point:

Lin was 22 years old, so he was relatively old for an NBA prospect (older players – as the above table notes – are taken later)

Lin is about 6ft. 3in. tall, or only about an inch bigger than an average point guard. So Lin isn’t short, but he isn’t exceptionally large either.

Lin did not play in the Final Four, NCAA Championship, or in a major conference. All of those would have helped his draft position. We should note, appearing in the Final Four only matters in the year the player is drafted; appearing in other years does not matter. Apparently, being a “winner” is a characteristic that wears off.

Lin averaged 16.4 points per game. This is about average for a point guard selected out of the college ranks by the NBA from 1995 to 2009. So Lin did not excel at the box score statistic that matters the most.

Lin was above average with respect to shooting from two-point range, steals, and blocked shots. But he was below average with respect to shooting from three-point range, assists, and personal fouls.

Finally, he was above average with respect to rebounding (for a point guard). But no matter how we considered rebounding (per game averages, per minute average, or rebounding percentages) we never found rebounding to impact a player’s draft position.

When we put the entire picture toge
ther, we should not be surprised that Lin wasn’t drafted. After all, he was a relatively old player from a minor conference that didn’t excel at scoring.

Of course Lin’s performance with the Knicks suggests that decision back in 2010 wasn’t correct. Was there anything in Lin’s college performance that would suggest that Lin would be a productive NBA player? Before we get to those numbers, it should be emphasized that college numbers are not a crystal ball into a player’s pro career. However, they are much better at predicting performance than whatever methods the NBA employs when making choices in the draft.

Let’s start with a summary of Lin’s numbers. Wins in basketball are primarily about shooting efficiency (i.e. the ability to put the ball in the basket), and your ability to gain and keep possession of the ball (i.e. rebounds, steals, and turnovers). The importance of these factors drives the calculation of Wins Produced. This model can be simplified into Win Score, which is calculated as follows:

An average point guard selected in the NBA draft from 1995 to 2009 posted a 5.8 Win Score per 40 minutes (WS40) in his last year in college. In 2009-10, Lin posted an 8.0 WS40, which meant he was an above average prospect.

Lin’s above average Win Score was driven by his ability to excel at shooting efficiency from two-point range, his ability to get rebounds, and his ability to get steals. When we look at which college factors predict an NBA player’s productivity, we find that it is these very same factors that matter: shooting efficiency from two-point range, rebounds, and steals.

Now what factors don’t matter? We found that a player’s height, age, and other box score numbers are not associated with more NBA production later on. In addition, appearing in the Final Four – a factor that clearly impacts draft position – doesn’t suggest higher production in the future. In sum, what Lin didn’t have in 2010 wasn’t related to his future NBA prospects. Consequently – contrary to what people in the NBA thought back in 2010 — people outside the NBA argued (again, back in 2010) that Lin might be worth a look.

The last team to overlook Lin was the Houston Rockets — they cut Lin back in December. At that time, the point guard the Rockets decided to keep was Jonny Flynn. Back in 2009, Flynn – after posting a 4.7 WS40 at Syracuse in 2008-09 (that is a below average mark) — was the 6th player taken in the NBA draft. As of last December, Flynn had played more than 3,300 minutes in the NBA and again posted below average numbers. Despite all this evidence that Flynn is not an above average basketball player, the Rockets kept Flynn over Lin.

What explain this “Flynnsanity”? Not only do NBA decision-makers focus on the wrong issues on the NBA draft, they also are slow to let these decisions go. A player’s draft position impacts minutes played – even after we control for performance – several years into a player’s career. So it’s not surprising that Flynn – who did not play well in college or in the NBA – was chosen by the Rockets over Lin. Flynn was supposed to be a star in college. He was supposed to be a star when he was drafted. And I am sure, people still believe Flynn may someday be a star in the NBA.

But given the consistency of NBA performance, it seems unlikely Flynn will ever be a star. And although the sample is still quite small, we now have even more evidence that Lin – contrary to what was thought by many (but not all) back in 2010 — will be a productive NBA player.

All this tells us is that although it’s much easier to evaluate talent in the NBA than the NFL, the results for teams in both leagues appear to be the same. And until decision makers in the NBA can do a better job of focusing on what matters – and ignoring what doesn’t – decisions in the NBA are likely to continue to look very much like what we see in the NFL.

Doug Chia

February 29, 2012 @ 5:07pm

A few omissions from the "Don’t Help Draft Position" or "Lower Draft Position" factors in your "What Explains Draft Position in the NBA?" analysis: (1) Being Asian American; and (2) Playing for an Ivy League school the year drafted. Historically, players with that exact combination have tended not to get looked at seriously at all. Whether that was conscious or unconscious on the part of the teams with draft picks and the professional draft predictors, it cannot be denied that this is at least part of the story here and why so many Asian Americans, like me, see this as a seminal moment in the history of American professional sports.

frankenduf

February 29, 2012 @ 6:29pm

so what's Yao?- chopped liver?

Doug Chia

February 29, 2012 @ 7:14pm

Totally different. Yao came into the NBA as "The Best Player Ever From China." Plus, anyone who is 7'0" or taller gets looked at differently than everyone else (e.g., Manute Bol, Shawn Bradley). Lin came in as a 6'3" Asian American kid who was considered by all major college programs as not worth a scholarship. Thus it was natural for the NBA to trust the college recruiting system as an initial filter that has been reliable in the past. In general, anyone coming from an Ivy League team has to prove beyond a reasonable doubt that they will pan out in the NBA. The NBA didn't miss on Lin as much as the college system did.

Alex D.

February 29, 2012 @ 5:42pm

This article is kind of absurd. So NBA decision-makers have a few biases towards scoring and Final Four appearances. That doesn't explain why they're fools for passing on a point guard with below-avg ASSISTS, that also doesn't play an *especially* large scoring role in a historically poor conference (compared with the majors, at least), and that doesn't project to shoot especially well (3-pointers are even harder with good wing defenders and longer shots).

Basically, if I'm a GM, just looking at the boxscore data without hindsight, I just passed on Jeremy Lin. Maybe more advanced stats would have validated what he showed in New York, but I think that this is your own hindsight (poorly argued) against the foresight of decision-makers choosing between dozens of possible options. Which is kind of a poor basis for calling them irrational.

gwadagibeht

February 29, 2012 @ 9:25pm

dude, there's a link labeled "BACK IN 2010". and regarding advanced stats, the entire article is about evaluating the draft using advanced stats (wins produced/win score) based on efficiency and rates...

jesse

February 29, 2012 @ 6:39pm

Could it possibly be that not being drafted led to the hardwork that Lin put in to have a breakout season? Or thay the reason he was cut from those teams is that they were only worried about keeping trade pieces?

Or we could continue this optimization problem of trying to figure out which stat Lin was above average at draft day.

DCJ

February 29, 2012 @ 6:44pm

Personally, I'm of the opinion that a major reason why Jeremy Lin was overlooked is because of his Asian heritage. That being said, I'm surprised that the player's race does not help draft position. I question though, the sample size of Asians in the study. A quick (non-fully researched) search online reveals that all previous Asian-Americans were drafted before 1995, so they're not represented in the study. Chinese players like Yao Ming and Yi JianLian were pro's in China and were already well-known when they declared. There's nobody similar to Jeremy Lin, so I think it's definitely a unique situation that can't be explained away by using statistics from '95-'09. While I think the study was interesting, I don't think it answers why Jeremy Lin was passed over so often.

On a side note, I think it's interesting that rebounds do not impact draft position. Rebounding seems like a more "glorified" stat than assists.
1. I think it might be that rebounds are sort of zero-sum, since someone else on the team will tend to pick up slack in rebounding.
2. Maybe there is a correlation between height and rebounding, so the influence of rebounding is indirectly factored into the influence of height.

Read more...

ronbo

February 29, 2012 @ 7:07pm

Am I correct in inferring that the stats that do and don't have an impact on draft position, such as rebounds, don't vary by position? Hard to imagine that guards and bigs are evaluated the same way. Or does that hold true for draft position but not actual performance?

Also, analysts keep talking about Lin's "basketball IQ". Even if some of that commentary reflects Lin being an Asian kid from Harvard, there seems to be plenty of evidence that he has very good floor vision and generally makes very good decisions - important qualities in a PG. What stats measure or serve as proxies for this quality?

BSK

February 29, 2012 @ 7:27pm

Lin's absurdly high TO rate shows that "decision-making" is not exactly one of his strengths. I am personally of the belief that the "basketball IQ" meme is grounded primarily in his race and secondarily in his alma mater. "Basketball IQ" is one of the words that is loaded and coded. Insiders constantly talked about Rasheed Wallace's elite basketball IQ; he supposedly was capable of stepping into any position for any offensive or defensive play and know exactly what to do. Yet this was a word that rarely got used with him outside these circles, because he didn't fit the popular trope of the "high basketball IQ" player.

Doug Chia

February 29, 2012 @ 7:37pm

Turnovers and basketball IQ are not necessarily related. Throwing the ball out of bounds and dribbling the ball off your foot and charging fouls are all TOs and have nothing to do with smart decision-making.

BSK

February 29, 2012 @ 7:29pm

Are we sure that the Knicks have HIT on Jeremy Lin? I mean, it's been what, 10 games? 12? From a marketing standpoint, he has obviously had a huge impact that could very well outlive his on court impact. But the sample size at this point is simply too small to make any final assessments.

Tallman

February 29, 2012 @ 10:51pm

I don't think this article needs Lin to continue to put up all star level numbers for it to be valid. And I do think it is fairly clear after ten games that he can at least help an NBA team compete. Watching him play, he continually takes his man off the dribble and gets to the rim. He did that during his first year in the league and he did that during D-league games. It is an elite skill and now he has really been doing this against professionals for two years. He has just done it more aggressively and for longer periods of time in games during this ten game stretch. But he was effective in supports last year. There is a reason Houston picked him up when Golden State waived him.

Even if he regresses to the level of quality backup, it means he was missed in the draft since the second round of the draft regularly have players who cannot stick in the league.

keith

Steve Fuzzgoo

February 29, 2012 @ 8:06pm

Our local paper had a good analysis of why he was not chosen, and it was because he simply was not good enough at the time. But he continued to work on his physical attributes and skills, to the point where he was finally capable of playing in the big show when the next chance presented itself. He clearly understood what he needed to do and kept at it.

danny

February 29, 2012 @ 9:10pm

Even Daryl Morey (Rockets GM), who went to MIT and has an undergrad from Northwestern in statistics, has acknowledged letting Lin go was a mistake. It is not an exact science, there are too many factors to consider.

Happily Left Out

March 1, 2012 @ 4:15am

You left out "How does a below average college player from a minor division appear to excel with a late entry into the NBA?"

Answer - Marketing.

Owners need to sell more tickets to pay all their high priced players, anyone willing to jeopardize that by putting professional levels of pressure on Lin is forgetting Basketball is a business and media frenzy is advertising.

Clearly you've wasted your time and skills feeding the beast.

Allen

March 1, 2012 @ 1:33pm

As a retired manager I have found the same failures in hiring practices at most of the companies I've worked for or applied at over my career. I had a much higher success rate of hiring than my peers for many years simply by taking HR out of the initial screening process. I had all applications sent directly to me and I selected the candidates that HR would set up for interviews.

I'd like to see the same review of the hiring decisions to see which predictors the HR department is using actually mean something and which are simply "how we've always done it".